Detecting transthyretin amyloid cardiomyopathy (ATTR-CM) using machine learning: an evaluation of the performance of an algorithm in a UK setting.

OBJECTIVE: The aim of this study was to evaluate the potential real-world application of a machine learning (ML) algorithm, developed and trained on heart failure (HF) cohorts in the USA, to detect patients with undiagnosed wild type cardiac amyloidosis (ATTRwt) in the UK. DESIGN: In this retrospective observational study, anonymised, linked primary and secondary care data (Clinical Practice Research Datalink GOLD and Hospital Episode Statistics, respectively, were used to identify patients diagnosed with HF between 2009 and 2018 in the UK. International Classification of Diseases (ICD)-10 clinical modification codes were matched to equivalent Read (primary care) and ICD-10 WHO (secondary care) diagnosis codes used in the UK. In the absence of specific Read or ICD-10 WHO codes for ATTRwt, two proxy case definitions (definitive and possible cases) based on the degree of confidence that the contributing codes defined true ATTRwt cases were created using ML. PRIMARY OUTCOME MEASURE: Algorithm performance was evaluated primarily using the area under the receiver operating curve (AUROC) by comparing the actual versus algorithm predicted case definitions at varying sensitivities and specificities. RESULTS: The algorithm demonstrated strongest predictive ability when a combination of primary care and secondary care data were used (AUROC: 0.84 in definitive cohort and 0.86 in possible cohort). For primary care or secondary care data alone, performance ranged from 0.68 to 0.78. CONCLUSION: The ML algorithm, despite being developed in a US population, was effective at identifying patients that may have ATTRwt in a UK setting. Its potential use in research and clinical care to aid identification of patients with undiagnosed ATTRwt, possibly enabling earlier diagnosis in the disease pathway, should be investigated.

Opioid use and patient outcomes in an Australian hip and knee arthroplasty cohort.

BACKGROUND: To determine the prevalence of opioid use in Australian hip (THA) or knee (TKA) cohort, and its association with outcomes. METHODS: About 837 primary THA or TKA subjects prospectively completed Oxford Scores, and Knee or Hip Osteoarthritis Outcomes Score(KOOS/HOOS) and opioid use in the previous week before arthroplasty. Subjects repeated the baseline survey at 6 months, with additional questions regarding satisfaction. RESULTS: Opioid use was reported by 19% preoperatively and 7% at 6 months. Opioid use was 46% at 6 weeks and 10% at 6 months after TKR, and 16% at 6 weeks and 4% at 6 months after THR. Preoperative opioid use was associated with back pain(OR 2.2, P = 0.006), anxiety or depression(OR 1.8, P = 0.001) and Oxford knee scores <30(OR 5.6, P = 0.021) in TKA subjects, and females in THA subjects(OR 1.7, P = 0.04). There was no difference between preoperative opioid users and non-users for satisfaction, or KOOS or HOOS scores at 6 months. 77% of patients taking opioids before surgery had ceased by 6 months, and 3% of preoperative non users reported opioid use at 6 months. Opioid use at 6 months was associated with preoperative use (OR 6.6-14.7, P < 0.001), and lower 6 month oxford scores (OR 4.4-83.6, P < 0.01). CONCLUSION: One in five used opioids before arthroplasty. Pre-operative opioid use was the strongest risk factor for opioid use at 6 months, increasing odds 7-15 times. Prolonged opioid use was rarely observed in the opioid naïve (<5% TKA and 1% THA). Preoperative opioid use was not associated with inferior outcomes or satisfaction.

Epidemiology of cardiomyopathies and incident heart failure in a population-based cohort study.

AIMS: The population prevalence of cardiomyopathies and the natural history of symptomatic heart failure (HF) and arrhythmia across cardiomyopathy phenotypes is poorly understood. Study aims were to estimate the population-diagnosed prevalence of cardiomyopathies and describe the temporal relationship between a diagnosis of cardiomyopathy with HF and arrhythmia. METHODS: People with cardiomyopathy (n=4116) were identified from linked electronic health records (~9 million individuals; 2000-2018) and categorised into hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), restrictive cardiomyopathy (RCM) and cardiac amyloidosis (CA). Cardiomyopathy point prevalence, rates of symptomatic HF and arrhythmia and timing relative to a diagnosis of cardiomyopathy were determined. RESULTS: In 2018, DCM was the most common cardiomyopathy. DCM and HCM were twice as common among men, with the reverse trend for ARVC. Between 2010 and 2018, prevalence increased for ARVC by 180% and HCM by 9%. At diagnosis, more patients with CA (66%), DCM (56%) and RCM (62%) had pre-existing HF compared with ARVC (29%) and HCM (27%). Among those free of HF at diagnosis of cardiomyopathy, annualised HF incidence was greatest in CA and DCM. Diagnoses of all cardiomyopathies clustered around the time of HF onset. CONCLUSIONS: The recorded prevalence of all cardiomyopathies increased over the past decade. Recognition of CA is generally preceded by HF, whereas individuals with ARVC or HCM more often developed HF after their cardiomyopathy diagnosis suggesting a more indolent course or better asymptomatic recognition. The clustering of HF and cardiomyopathy diagnoses suggests opportunities for presymptomatic or earlier diagnosis.

Insulin-like growth factor-1, growth hormone and disease outcomes in acromegaly: A population study.

CONTEXT: A lack of consensus remains about the relative importance of insulin-like growth factor-1 (IGF-1) and growth hormone (GH) in predicting adverse outcomes in patients with acromegaly. OBJECTIVE: To describe the differing association between IGF-1 and GH and major disease outcomes in acromegaly. DESIGN: Retrospective cohort study. PATIENTS: United Kingdom National Health Service patients with acromegaly who had an IGF-1 and/or a GH measurement recorded following diagnosis, prior to December 2019. MEASUREMENTS: A composite endpoint including all-cause mortality (ACM), type 2 diabetes (DM), major adverse cardiovascular events (MACE) or cancer was the primary outcome. These outcomes were also analysed individually. Follow-up period was capped at 5 years. RESULTS: A maximum of 417 cases and 332 cases were eligible for the IGF-1 and GH analyses, respectively, comprising 1041.5 and 938.9 years of follow-up. There was a direct association between increased IGF-1 concentration and adjusted event risk for the composite endpoint (hazard ratio [HR] = 1.2; 95% confidence interval [CI] = 1.02-1.5); in GH, the HR was 1.1 (1.0-1.2). For the individual endpoints in relation to IGF-1 level, the HRs were ACM (1.2; 0.93-1.5), MACE (1.2; 0.64-2.1), DM (1.53; 1.09-2.2) and cancer (1.3; 0.95-1.7). For GH, the HRs were ACM (1.1; 0.97-1.2), MACE (0.99; 0.73-1.3), DM (1.1; 0.99-1.2) and cancer (0.90; 0.66-1.2). CONCLUSIONS: In this contemporary data set with extended follow-up, IGF-1 and GH concentrations showed an association with major adverse outcomes from acromegaly.

Diagnostic performance of imaging investigations in detecting and differentiating cardiac amyloidosis: a systematic review and meta-analysis.

AIMS: The study aims to systematically assess the diagnostic performance of cardiac magnetic resonance (CMR) and nuclear scintigraphy (index tests) for the diagnosis and differentiation of subtypes of cardiac amyloidosis. METHODS AND RESULTS: MEDLINE and Embase electronic databases were searched for studies evaluating the diagnostic performance of CMR or nuclear scintigraphy in detecting cardiac amyloidosis and subsequently in differentiating transthyretin amyloidosis (ATTR) from immunoglobulin light-chain (AL) amyloidosis. In this meta-analysis, histopathological examination of tissue from endomyocardial biopsy (EMB) or extra-cardiac organs were reference standards. Pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were calculated, and a random effects meta-analysis was used to estimate diagnostic odds ratios. Methodological quality was assessed using a validated instrument. Of the 2947 studies identified, 27 met the criteria for inclusion. Sensitivity and specificity of CMR in diagnosing cardiac amyloidosis was 85.7% and 92.0% against EMB reference and 78.9% and 93.9% with any organ histology reference. Corresponding sensitivity and specificity of nuclear scintigraphy was 88.4% and 87.2% against EMB reference and 82.0% and 98.8% with histology from any organ. CMR was unable to reliably differentiate ATTR from AL amyloidosis (sensitivity 28.1-99.0% and specificity 11.0-60.0%). Sensitivity and specificity of nuclear scintigraphy in the differentiation of ATTR from AL amyloidosis ranged from 90.9% to 91.5% and from 88.6% to 97.1%. Pooled negative likelihood ratio and positive likelihood ratio for scintigraphy in this setting were 0.1 and 8, with EMB reference standard. Study quality assessed by QUADAS-2 was generally poor with evidence of bias. CONCLUSIONS: Cardiac magnetic resonance is a useful test for diagnosing cardiac amyloidosis but is not reliable in further classifying the disease. Nuclear scintigraphy offers strong diagnostic performance in both the detection of cardiac amyloidosis and differentiating ATTR from AL amyloidosis. Our findings support the use of both imaging modalities in a non-invasive diagnostic algorithm that also tests for the presence of monoclonal protein.

A Systematic Review of Predictors of Reintervention After EVAR: Guidance for Risk-Stratified Surveillance.

BACKGROUND: Current surveillance protocols after endovascular aneurysm repair (EVAR) are ineffective and costly. Stratifying surveillance by individual risk of reintervention requires an understanding of the factors involved in developing post-EVAR complications. This systematic review assessed risk factors for reintervention after EVAR and proposals for stratified surveillance. METHODS: A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting on risk factors predicting reintervention after EVAR and proposals for stratified surveillance. RESULTS: Twenty-nine studies reporting on 39 898 patients met the primary inclusion criteria for reporting predictors of reintervention or aortic complications with or without suggestions for stratified surveillance. Five secondary studies described external validation of risk scores for reintervention or aortic complications. There was great heterogeneity in reporting risk factors identified at the pre-EVAR, intraoperative, and post-EVAR stages of treatment, although large preoperative abdominal aortic aneurysm diameter was the most commonly observed risk factor for reintervention after EVAR. CONCLUSION: Existing data on predictors of post-EVAR complications are generally of poor quality and largely derived from retrospective studies. Few studies describing suggestions for stratified surveillance have been subjected to external validation. There is a need to refine risk prediction for EVAR failure and to conduct prospective comparative studies of personalized surveillance with standard practice.

Abnormal Remodeling of Subcutaneous Small Arteries Is Associated With Early Diastolic Impairment in Metabolic Syndrome.

BACKGROUND: Small artery pathophysiology is frequently invoked as a cause of obesity-related diastolic heart failure. However, evidence to support this hypothesis is scant, particularly in humans. METHODS AND RESULTS: To address this, we studied human small artery structure and function in obesity and looked for correlations between vascular parameters and diastolic function. Seventeen obese patients with metabolic syndrome and 5 control participants underwent echocardiography and subcutaneous gluteal fat biopsy. Small arteries were isolated from the biopsy and pressure myography was used to study endothelial function and wall structure. In comparison with the control group, small arteries from obese participants exhibited significant endothelial dysfunction, assessed as the vasodilatory response to acetylcholine and also pathological growth of the wall. For the obese participants, multiple regression analysis revealed an association between left atrial volume and both the small artery wall thickness (ß=0.718, P=0.02) and wall-to-lumen ratio (ß=0.605, P=0.02). Furthermore, the E:E' ratio was associated with wall-to-lumen ratio (ß=0.596, P=0.02) and inversely associated with interleukin-6 (ß=-0.868, P=0.03). By contrast, endothelial function did not correlate with any of the echocardiographic parameters studied. CONCLUSIONS: Although the small arteries studied were not cardiac in origin, our results support a role for small artery remodeling in the development of diastolic dysfunction in humans. Further direct examination of the structure and function of the myocardial resistance vasculature is now warranted, to elucidate the temporal association between metabolic risk factors, small artery injury, and diastolic impairment.

Endovascular treatment of mycotic aortic aneurysms: a European multicenter study.

BACKGROUND: Mycotic aortic aneurysm (MAA) is a rare and life-threatening disease. The aim of this European multicenter collaboration was to study the durability of endovascular aortic repair (EVAR) of MAA, by assessing late infection-related complications and long-term survival. METHODS AND RESULTS: All EVAR treated MAAs, between 1999 and 2013 at 16 European centers, were retrospectively reviewed. One hundred twenty-three patients with 130 MAAs were identified. Mean age was 69 years (range 39-86), 87 (71%) were men, 58 (47%) had immunodeficiency, and 47 (38%) presented with rupture. Anatomic locations were ascending/arch (n=4), descending (n=34), paravisceral (n=15), infrarenal aorta (n=63), and multiple (n=7). Treatments were thoracic EVAR (n=43), fenestrated/branched EVAR (n=9), and infrarenal EVAR (n=71). Antibiotic was administered for mean 30 weeks. Mean follow-up was 35 months (range 1 week to 149 months). Six patients (5%) were converted to open repair during follow-up. Survival was 91% (95% confidence interval, 86% to 96%), 75% (67% to 83%), 55% (44% to 66%), and 41% (28% to 54%) after 1, 12, 60, and 120 months, respectively. Infection-related death occurred in 23 patients (19%), 9 after discontinuation of antibiotic treatment. A Cox regression analysis demonstrated non-Salmonella-positive culture as predictors for late infection-related death. CONCLUSIONS: Endovascular treatment of MAA is feasible and for most patients a durable treatment option. Late infections do occur, are often lethal, and warrant long-term antibiotic treatment and follow-up. Patients with non-Salmonella-positive blood cultures were more likely to die from late infection.

Peripheral neuropathy and the risk of cardiovascular events in type 2 diabetes mellitus.

AIMS: Identifying individuals with diabetes at high risk of cardiovascular disease (CVD) remains challenging. We aimed to establish whether peripheral neuropathy (PN) is associated with incident CVD events and to what extent information on PN may improve risk prediction among individuals with type 2 diabetes. METHODS: We obtained data for individuals with type 2 diabetes, and free of CVD, from a large primary care patient cohort. Incident CVD events were recorded during a 30-month follow-up period. Eligible individuals had complete ascertainment of cardiovascular risk factors and PN status at baseline. The association between PN and incident CVD events (non-fatal myocardial infarction, coronary revascularisation, congestive cardiac failure, transient ischaemic attack and stroke) was evaluated using Cox regression, adjusted for standard CVD risk factors. We assessed the predictive accuracy of models including conventional CVD risk factors with and without information on PN. RESULTS: Among 13 043 eligible individuals, we recorded 407 deaths from any cause and 399 non-fatal CVD events. After adjustment for age, sex, ethnicity, systolic blood pressure, cholesterol, body mass index, HbA1c, smoking status and use of statin or antihypertensive medication, PN was associated with incident CVD events (HR 1.33; 95% CI 1.02 to 1.75, p=0.04). The addition of information on PN to a model based on standard CVD risk factors resulted in modest improvements in discrimination for CVD risk prediction and reclassified 6.9% of individuals into different risk categories. CONCLUSIONS: PN is associated with increased risk for a first cardiovascular event among individuals with diabetes.

Influence of foot ulceration on cause-specific mortality in patients with diabetes mellitus.

OBJECTIVE: The purpose of this study was to assess the odds of all-cause mortality in individuals with diabetic foot ulceration (DFU) compared with those with diabetes and no history of DFU. In addition, we sought to determine the strength of association of DFU with cardiovascular and nonvascular mortality. METHODS: We obtained data for a cohort of patients who attended a secondary care diabetic foot clinic or a general diabetes clinic between 2009 and 2010. A clinic cohort of patients with diabetes and no history of DFU provided a control group. Cause-specific mortality was recorded during a median follow-up duration of 3.6 years (interquartile range, 3.3-4.2 years). The association between DFU and all-cause mortality was evaluated by Cox regression. The association between DFU and cardiovascular mortality was determined by competing risk modeling. RESULTS: We recorded 145 events of all-cause mortality and 27 events of cardiovascular mortality among 869 patients with diabetes. After adjustment for potential confounders, DFU was associated with both cardiovascular disease (hazard ratio, 2.53; 95% confidence interval, 0.98-6.49; P = .05) and all-cause mortality (hazard ratio, 3.98; 95% confidence interval, 2.55-6.21; P < .001). The proportion of deaths attributable to cardiovascular disease was similar between the groups (18% with diabetes only and 19% with DFU; P = .91). CONCLUSIONS: DFU is associated with premature death from vascular and nonvascular causes.

Interrupting the natural history of diabetes mellitus: lifestyle, pharmacological and surgical strategies targeting disease progression.

In recent decades we have seen a surge in the incidence of diabetes in industrialized nations; a threat which has now extended to the developing world. Type 2 diabetes is associated with significant microvascular and macrovascular disease, with considerable impact on morbidity and mortality. Recent evidence has cast uncertainty on the benefits of very tight glycaemic goals in these individuals. The natural history of disease follows an insidious course from disordered glucose metabolism in a pre-diabetic state, often with metabolic syndrome and obesity, before proceeding to diabetes mellitus. In the research setting, lifestyle, pharmacological and surgical intervention targeted against obesity and glycaemia has shown that metabolic disturbances can be halted and indeed regressed if introduced at an early stage of disease. In addition to traditional anti-diabetic medications such as the glinides, sulphonylureas and the glitazones, novel therapies manipulating the endocannabinoid system, neurotransmitters, intestinal absorption and gut hormones have shown dual benefit in weight loss and glycaemic control normalisation. Whilst these treatments will not and should not replace lifestyle change, they will act as invaluable adjuncts for weight loss and aid in normalising the metabolic profile of individuals at risk of diabetes. Utilizing novel therapies to prevent diabetes should be the focus of future research, with the aim of preventing the challenging microvascular and macrovascular complications, and ultimately cardiovascular death.

Systematic review of screening investigations for peripheral arterial disease in patients with diabetes mellitus.

Diabetes-related foot complications are a major cause of amputation. The presence of peripheral arterial disease (PAD) identifies those at increased risk of ulceration, failure to heal an ulcer, and amputation. This systematic review assesses the ability of noninvasive screening tests to detect PAD in patients with diabetes mellitus. A database search was performed using the OVIDSP Web site, from 1946 to June 30, 2012 (MEDLINE®), and from 1974 to June 30, 2012 (EMBASE), to identify studies assessing the utility of screening tests in detecting PAD or predicting clinical outcomes in patients with diabetes mellitus. Thirteen studies were identified that reported sensitivity and specificity data on screening tests. No single screening test was reliable in identifying or excluding peripheral arterial disease in patients with diabetes. Although the evidence base is limited, transcutaneous oxygen measurements appear to be predictive of ulcer or surgical wound healing. The diagnosis of PAD (and the decision to revascularize) in patients with diabetes is unreliable using screening tests. Therefore, all patients with diabetes-related foot ulceration should be assessed by a multidisciplinary diabetes foot team that has access to a vascular specialist. A low threshold for noninvasive diagnostic imaging seems appropriate in patients with diabetes-related foot ulceration.

The BASIL survival prediction model in patients with peripheral arterial disease undergoing revascularization in a university hospital setting and comparison with the FINNVASC and modified PREVENT scores.

BACKGROUND: Critical limb ischemia carries a significant risk of morbidity and mortality. The development of scores to predict risk can aid clinical decision making. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial investigators developed a model to predict death, which has not been previously validated. METHODS: Data were collected in a prospectively maintained database on all patients who underwent angioplasty or arterial bypass for peripheral artery disease in a university hospital between January 2008 and June 2010. The main outcome measures were all-cause mortality and amputation-free survival at 3, 6, 12, and 24 months after the index intervention. The BASIL survival predictor, Finland National Vascular (FINNVASC) registry, and Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT) models were applied and receiver-operating characteristic (ROC) curve analysis was used to evaluate their predictive power. RESULTS: Data on 342 patients were collected. Patients with isolated iliac disease or claudication were excluded. The 6-, 12-, and 24-month all-cause mortality rates were 11.6%, 17.9%, and 26.8%, respectively. The area under the ROC curve (95% confidence interval) using the BASIL score to predict mortality at 6, 12, and 24 months was 0.700 (0.60-0.80; P<.001), 0.651 (0.56-0.74; P<.003), and 0.681 (0.59-0.74; P<.001), respectively. ROC curve analysis indicated that the performance of the BASIL score in this cohort was comparable to other validated predictive scores. CONCLUSIONS: The BASIL survival prediction model can moderately predict short-term and medium-term mortality in patients with limb ischemia and may be a useful adjunct to decision making in everyday clinical practice.

Acute rupture of a fibromuscular dysplasia related renal artery aneurysm: emergency treatment with a covered stent.

We report the successful exclusion of a ruptured left renal artery aneurysm as a first presentation of fibromuscular dysplasia in a haemodynamically unstable 57-year-old man. The aneurysm was repaired in an emergency setting by deployment of a covered stent with a satisfactory result. Follow-up computed tomography confirmed successful exclusion of the aneurysm. A renal artery branch originating from the aneurismal sac was sacrificed with subsequent regional infarction. Our experience shows that the use of a covered stent is an effective, quick and life saving procedure in a ruptured renal artery aneurysm.